These cognitive disturbances are not better explained by another preexisting, established, or evolving neurocognitive disorder and do not occur in the context of a severely reduced level of arousal, such as coma.

There is evidence from the history, physical examination, or laboratory findings that the disturbance is a direct physiological consequence of another medical condition, substance intoxication or withdrawal (i.e., due to a drug of abuse or to a medicatioin), or exposure to a toxin, or is due to multiple etiologies.

Effective Therapies

Outcome depends on the physical cause of the delirium. Antipsychotic medication [1], high-dose lorazepam, or electroconvulsive therapy (ECT) is effective for the delirium caused by bipolar I disorder [2][3]. Neuroleptic malignant syndrome (caused by antipsychotic medication) and serotonin syndrome (caused by SSRI antidepressant medication) can both cause delirium. Many other medications and medical disorders can cause delirium.